Light emitting device, electronic equipment, and organic polarizing film

ABSTRACT

A light emitting device capable of reducing degradation caused by dispersion of impurities such as moisture, oxygen, an alkaline metal, and an alkaline earth metal is provided. Specifically, a flexible light emitting device with an OLED formed on a plastic substrate is provided. In a light emitting device using a substrate, a circular polarizing plate has a single layer or two or more layers of barrier films formed of a compound or compounds selected from AlN X O Y , Al X N Y , and Al 2 O 3 , which is (are) capable of preventing oxygen and moisture from seeping into an organic light emitting layer of an OLED as well as preventing an alkaline metal, an alkaline earth metal, and other impurities from penetrating an active layer of a TFT.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a light emitting device,especially, a light emitting device and an electronic equipment havingan organic light emitting diode (OLED) formed on a plastic substrate.Further, the present invention relates to an OLED module wherein ICsincluding a controller and the like are mounted on the OLED panel. Inthis specification, the light emitting device is a general term for theOLED panel and the OLED module.

[0003] 2. Description of the Related Art

[0004] In recent years, a technology constituting a thin film transistor(TFT) using a semiconductor thin film (in the range from about a few toa few hundreds nm in thickness) formed on the substrate having aninsulating surface has drawn attention. A thin film transistor is widelyapplied to electronic devices such as an IC, an electro-optic device orthe like, and particularly, there is an urgent need to be developed as aswitching element for an image display device.

[0005] Although as for applications utilizing such an image displaydevice, a variety of applications are expected, particularly, itsutilization for portable apparatuses has drawn the attention. Atpresent, although many glass substrates and quartz substrates areutilized, there are defaults of being easily cracked and heavy.Moreover, the glass substrates and quartz substrates are difficult to bemade larger in terms of conducting a mass-production, and these are notsuitable for that. Therefore, the attempt that a TFT element is formedon a substrate having flexibility, representatively, on a flexibleplastic film has been performed.

[0006] However, since the heat resistance of a plastic film is low, itcannot help lowering the highest temperature of the process. As aresult, at present, a TFT is formed which has not so excellent electriccharacteristics compared with those formed on the glass substrates.Therefore, a light emitting element having a high performance byutilizing a plastic film have not been realized yet.

[0007] In these years, research of an active matrix type light emittingdevice (hereinafter, simply referred to as a light emitting device)having a light emitting diode as a self-luminescence type element isintensified. The light emitting device is also called as an organic ELdisplay (OELD) or an organic light emitting diode (OLED).

[0008] The OLED has high visibility since it emits light for itself anddoes not need a backlight which is necessary in a liquid crystal display(LCD), and it is optimum to be made thinner, and there is no limitationabout a visual field angle. Therefore, a light emitting device using theOLED is noticed as a display device taking the place of CRTs and LCDs.

[0009] In case that it becomes possible to make a light emitting devicein which an organic light emitting element is formed on a substratehaving flexibility such as plastic film, it is thin in thickness and oflight weight and can be used for a display having a curved surface and ashow window. Therefore, its application is not limited only to portableapparatuses but it has a broader range of applications.

[0010] However, a substrate comprising a plastic is generally easy totransmit moisture and oxygen through it, and deterioration of an organiclight emitting layer is expedited by these staffs, and therefore, alight emitting device is particularly easy to be short-lived. Thus, inthe related art, an insulating film which comprises silicon nitride andsilicon oxynitride is disposed between a plastic substrate and an OLEDso that mixture of moisture and oxygen in the organic light emittinglayer is prevented. However, in the insulating film which comprisessilicon nitride and silicon nitride oxide, it is hard to adequatelyprevent moisture and oxygen from being mixed in the organic lightemitting layer.

[0011] In addition, a substrate such as a plastic film is generally weakagainst heat, and in case that temperature for forming an insulatingfilm such as silicon nitride and silicon oxynitride is raised too much,the substrate is made to be easily transformed. Further, in case thatfilm forming temperature is too low, film characteristic is deterioratedso that it becomes hard to adequately prevent moisture and oxygen frombeing mixed.

[0012] Further, in case that driven is an element which is disposed onthe substrate such as the plastic film, it becomes an issue that heat isdeveloped locally so that a part of the substrate is transformed anddegenerated.

[0013] Furthermore, in case that thickness of the insulating film suchas silicon nitride and silicon oxynitride is increased in order toprevent moisture and oxygen from being mixed, stress is enlarged so thatit becomes easy to suffer some cracks. Moreover, in case that filmthickness is increased, the film is apt to suffer some cracks when thesubstrate is bent. Further, when the substrate is peeled off, a layer tobe peeled off is bent and the layer to be peeled off suffers somecracks.

[0014] Further, in case of a TFT, when impurities such as an alkalinemetal (Li, Cs, Na etc.) and an alkaline earth metal (Ca, Mg etc.) andother metal elements are diffused in an active layer in addition tomoisture and oxygen, characteristic is apt to be changed.

[0015] Furthermore, even after final products are made, in case thatother impurities, for example, human sweat and impurities fromconnecting components, are diffused and mixed in the light emittinglayer and the active layer of TFT, there is a possibility thatdegeneration and deterioration are expedited.

SUMMARY OF THE INVENTION

[0016] The present invention is, in light of the above problems, toprovide a light emitting device which is capable of suppressingdeterioration due to diffusion of impurities such as moisture, oxygen,an alkaline metal and an alkaline earth metal, and concretely, a lightemitting device having the OLED which is formed on the plasticsubstrate.

[0017] In general, light emitting devices having OLEDs are provided witha polarizing means called a circular polarizing plate as anantireflection means for preventing background images from beingreflected on the screen. A light emitting element having circularpolarizing means on its light exit side is disclosed in JP 09-127885 A.

[0018] The present invention is characterized in that a circularpolarizing plate, which is interposed between a light emitting elementand a viewer (observer), has on its one side or each side a single layeror multilayer of a compound or compounds selected from AlN_(X)O_(Y),Al_(X)N_(Y), and Al₂O₃ (the layer(s) may also be called a barrier film(barrier films) below), which is (are) capable of preventing oxygen andmoisture from seeping into an organic light emitting layer of an OLED aswell as preventing an alkaline metal, an alkaline earth metal, and otherimpurities from penetrating an active layer of a TFT. Preferably, thecircular polarizing plate is sandwiched between plural barrier films toprevent oxygen and moisture from seeping into an organic light emittinglayer of an OLED.

[0019] In this specification, a circular polarizing plate refers to anantireflection means for preventing background images from beingreflected on a screen of a light emitting device having an OLED.Specifically, a circular polarizing plate (including an ellipticalpolarizing plate) is a combination of a phase difference plate (λ/4plate) or a phase difference film and a polarizing plate, or apolarizing film, or a linear polarizing film. Background images beingreflected on a screen means that viewer's face, ceiling, and othersurroundings are reflected on a display unit of a light emitting devicedue to reflection by a cathode or the like. To elaborate, a polarizingplate and a phase difference film with their polarization axes formingan angle of 45° make a circular polarizing plate. When the polarizationaxes of a polarizing plate and a phase difference film form an angle of45°, light entering the polarizing plate from the outside is changedinto linearly-polarized light by passing through the polarizing plateand then twisted by 45° and changed into elliptically-polarized light bythe phase difference film. The elliptically-polarized light is reflectedby a cathode and changed into linearly-polarized light by the phasedifference film. The linearly-polarized light and the polarization axisof the polarizing plate form an angle of 90° and therefore the reflectedlight is absorbed by the polarizing plate. Accordingly, a phasedifference film and a polarizing plate are set in a light emittingdevice in a manner that keeps a viewer from seeing background imagesreflected on the screen. As described, a light emitting device employs acircular polarizing plate to prevent light that has entered the devicefrom the outside from exiting the device upon being reflected by acathode. In this specification, the term circular polarizing plateincludes a circular polarizing film.

[0020] The present invention is applicable to passive matrix devices andactive matrix devices both, and is not limited to any particular drivingmethod.

[0021] A structure of the present invention disclosed in thisspecification is a light emitting device with a light emitting elementhaving a cathode, an organic compound layer, and an anode, the organiccompound layer being in contact with the cathode, the anode being incontact with the organic compound layer, characterized in that the lightemitting device is provided with a circular polarizing plate having asingle layer or multilayer of AlN_(X)O_(Y).

[0022] In the above structure, the light emitting device ischaracterized in that the circular polarizing plate has a single layeror multilayer of AlN_(X)O_(Y) on one side thereof or on each sidethereof. The circular polarizing plate having a single layer ormultilayer of AlN_(X)O_(Y) on one side thereof or on each side thereofmay be used as a sealing member, a supporting member, or a cover memberin order to reduce the weight of the light emitting device more.

[0023] In the above structure, the light emitting device ischaracterized in that the circular polarizing plate has a single layeror multilayer of AlN_(X)O_(Y) on one side thereof and has a bondingmember on the other side thereof. In the above structures, the lightemitting device is characterized in that the circular polarizing plateis interposed between the light emitting element and a viewer(observer), and is positioned at some point along the light path thatstarts with emission of light from the light emitting element and endswith arrival of the light at the viewer.

[0024] In the above structures, the light emitting device ischaracterized in that the AlN_(X)O_(Y) layer(s) contain(s) 2.5 to 47.5atm % of nitrogen. This way the layer(s) can block moisture and oxygenand become(s) highly heat-conductive to obtain a heat radiation effect.In addition, the layer(s) can prevent an alkaline metal, an alkalineearth metal, and other impurities from penetrating an active layer of aTFT. In the above structures, the light emitting device is characterizedin that the AlN_(X)O_(Y) layer(s) is (are) 50 to 500 nm in thickness.

[0025] The present invention may be a light emitting device sandwichedbetween a pair of substrates. Accordingly, another structure of thepresent invention is a light emitting device with a light emittingelement sandwiched between a first substrate and a second substrate, thelight emitting element having a cathode, an organic compound layer, andan anode, the organic compound layer being in contact with the cathode,the anode being in contact with the organic compound layer, the devicebeing characterized in that the first substrate or the second substrateis provided with a circular polarizing plate having a single layer ormultilayer of a compound or compounds selected from AlN_(X)O_(Y),Al_(X)N_(Y), and Al₂O₃.

[0026] In the above structure, the light emitting device ischaracterized in that the circular polarizing plate is fixed to thefirst substrate or the second substrate by a bonding member.

[0027] When the circular polarizing plate having an AlN_(X)O_(Y) layer,and/or an Al_(X)N_(Y) layer, and/or an Al₂O₃ layer is provided on one ofthe substrates (the light exit side) and the other substrate is aplastic substrate, desirably two or more layers of barrier filmscomposed of AlN_(X)O_(Y) layers, and/or Al_(X)N_(Y) layer, and/or Al₂O₃layers are formed on the plastic substrate and a stress relaxing filmcontaining a resin (hereinafter referred to as stress relaxing film) isinterposed between two adjacent layers of the two or more barrier films.Then an OLED is formed on three or more layers of insulating films andsealed to complete a light emitting device.

[0028] Alternatively, the circular polarizing plate may have two or morelayers of barrier films composed of AlN_(X)O_(Y) layers, and/orAl_(X)N_(Y) layers, and/or the Al₂O₃ layers and a stress relaxing filmis interposed between two adjacent layers of the two or more barrierfilms.

[0029] The above structure, namely, a laminate of barrier films andstress relaxing films formed on the circular polarizing plate or theplastic substrate, makes the device more flexible and can prevent thedevice from cracking when it is bent.

[0030] With a plurality of barrier films composed of AlN_(X)O_(Y)layers, and/or Al_(X)N_(Y) layers, and/or Al₂O₃ layers layered on thecircular polarizing plate or the plastic substrate, a crack in one ofthe barrier films is not a problem since the rest of the barrier filmseffectively prevent permeation of moisture, oxygen, and other impuritiesinto the organic light emitting layer as well as penetration of analkaline metal and like other impurities into the active layer of theTFT.

[0031] By sandwiching a stress relaxing film that is smaller in stressthan a barrier film between barrier films, the entire stress can beeased. Therefore barrier films sandwiching a stress relaxing film isless likely to be cracked by stress than a single-layered barrier filmeven if the total thickness of the former is the same as the thicknessof the latter.

[0032] The following combinations can be employed as the laminate ofbarrier films and stress relaxing films: an AlN_(X)O_(Y) layer (a firstbarrier film), an organic resin layer that is in contact with the firstbarrier film, and an AlN_(X)O_(Y) layer (a second barrier film) that isin contact with the organic resin layer; an organic resin layer (a firststress relaxing film), an AlN_(X)O_(Y) layer that is in contact with thefirst stress relaxing film, and an organic resin layer (a second stressrelaxing film) that is in contact with the AlN_(X)O_(Y) layer; and anAlN_(X)O_(Y) layer (a first barrier film), an organic resin layer thatis in contact with the first barrier film, and an Al₂O₃ layer (a secondbarrier film) that is in contact with the organic resin layer.

[0033] The AlN_(X)O_(Y) layer(s) formed on the circular polarizing plateor the plastic substrate may have a concentration gradient so that alarger amount of nitrogen is contained on the side close to the lightemitting element and the nitrogen content becomes smaller as thedistance from the light emitting element is increased. If a barrier filmis an AlN_(X)O_(Y) layer having a nitrogen concentration gradient asthis, the total thickness of the barrier film can be reduced to improvethe entire light transmittance.

[0034] In the present invention, if the direction in which light emittedfrom the light emitting element exits the device is to be chosen, it ispreferred for the light to pass the substrate provided with the circularpolarizing plate to be recognized by a viewer (user).

[0035] To sandwich the light emitting element between two substrates,the substrates are bonded to each other by a bonding layer. However, thebonding layer allows moisture, oxygen, and other impurities to permeateeven if barrier films are formed on both substrates. Therefore,preferably a single layer or multilayer of a compound or compoundsselected from AlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃ is (are) used as apassivation film (passivation films, also called protective films) forcovering the light emitting element and the light emitting element iswrapped with the barrier film(s) and the passivation film(s). Inaddition, the light emitting element may be covered with two or morelayers of passivation films composed of AlN_(X)O_(Y) layers, and/orAl_(X)N_(Y) layers, and/or Al₂O₃ layers and a stress relaxing filmcontaining a resin (hereinafter referred to as stress relaxing film) isinterposed between two adjacent layers of the two or more passivationfilms. By sandwiching a stress relaxing film that is smaller in stressthan a passivation film between passivation films, the entire stress canbe eased.

[0036] In the above structures, the organic resin layer is characterizedby being formed from a single layer or multilayer of a material that issmaller in stress than Al_(X)N_(Y), for example, a material selectedfrom polyimide, acrylic, polyamide, polyimideamide, benzocyclobutene, oran epoxy resin. In the above structures, the organic resin layer ischaracterized by including the bonding layer for bonding the substrates.

[0037] The AlN_(X)O_(Y) layer and Al_(X)N_(Y) layer in the abovestructures diffuse heat generated in the element to provide an effect ofreducing degradation of the element as well as an effect of protectingthe plastic substrate against deformation and alteration.

[0038] In the above respective structures, as long as the abovementioned plastic substrate has flexibility, it is not particularlylimited, and may be a plastic substrate selected from, for example,polyethylene terephthalate (PET), polyether sulfone (PES), polyethylenenaphthalate (PEN), polycarbonate (PC), nylon, polyether etherketone(PEEK), polysulfone (PSF), polyether imide (PEI), polyallylate (PAR),polybutylene terephthalate (PBT), or polyimide.

[0039] Further, another structure of the present invention is an organicpolarizing film having on its film surface a single layer or multilayerof a compound or compounds selected from AlN_(X)O_(Y), Al_(X)N_(Y), andAl₂O₃.

[0040] In the above structure, the single layer or multilayer of acompound or compounds selected from AlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃is (are) 50 to 500 nm thick in total.

[0041] In this specification, all layers provided between a cathode andan anode of an OLED are generically defined as organic light emittinglayers. Specifically, a light emitting layer, a hole injection layer, anelectron injection layer, a hole transporting layer, an electrontransporting layer and the like are all included in the category oforganic light emitting layers. The OLED basically has a structure inwhich an anode, a light emitting layer and a cathode are layered in thestated order. In addition to this structure, some OLEDs have a structureincluding an anode, a hole injection layer, a light emitting layer and acathode layered in the stated order, and other OLEDs have a structureincluding an anode, a hole injection layer, a light emitting layer, anelectron transporting layer, a cathode and the like layered in thestated order.

[0042] The OLED includes: a layer containing an organic compound((organic light emitting material) hereinafter referred to as organiclight emitting layer), which generates luminescence(electroluminescence) by applying an electric field; an anode; and acathode. The electroluminescence generated from the organic compoundincludes: light emission (fluorescence) caused upon return from asinglet excited state to a ground state; and light emission(phosphorescence) caused upon return from a triplet excited state to aground state. The light emitting device of the present invention may useeither one of the above-described types of light emission;alternatively, it may use both types of light emission.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In the accompanying drawings:

[0044]FIG. 1 is a brief sectional view for explaining a light emittingdevice of the present invention;

[0045]FIGS. 2A and 2B are brief sectional views for explaining anorganic polarizing film of the present invention;

[0046]FIGS. 3A to 3D are diagrams showing a manufacturing process ofTFT;

[0047]FIGS. 4A to 4D are diagrams showing a manufacturing process ofTFT;

[0048]FIG. 5 is a cross sectional view showing an active matrixsubstrate on which an OLED is provided;

[0049]FIGS. 6A to 6C are process sectional views for explainingEmbodiment 3;

[0050]FIGS. 7A and 7B are process sectional views for explainingEmbodiment 3;

[0051]FIGS. 8A and 8B are cross sectional views of an EL module forexplaining Embodiment 4;

[0052]FIG. 9 is a cross sectional view of an EL module for explainingEmbodiment 5;

[0053]FIGS. 10A to 10F are diagrams showing an example of electronicequipments;

[0054]FIGS. 11A to 11C are diagrams showing an example of electronicequipments;

[0055]FIG. 12 is a graph showing transmission factor of AlN_(X)O_(Y)film of the present invention; and

[0056]FIG. 13 is an ESCA analysis result of AlN_(X)O_(Y) film of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] Embodiment modes of the present invention will be describedbelow.

[0058] Embodiment Mode 1

[0059]FIG. 1 is a simplified view of an example of a light emittingdevice according to the present invention.

[0060] First, a substrate 10 is prepared. On the substrate 10, a layer11 including an OLED or including an OLED and a TFT is formed. Noparticular limitation is put on the substrate 10 and a glass substrate,a quartz substrate, a silicon substrate, a metal substrate, or astainless steel substrate may be employed. For simplification, detailedstructures of the OLED and TFT are not shown in the drawing.

[0061] Next, a protective film (also called a passivation film) isformed to cover the layer 11 including an OLED or including an OLED anda TFT. The protective film is a single layer or multilayer of a compoundor compounds selected from AlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃. Here,AlN_(X)O_(Y) films are used.

[0062] Prepared next is a circular polarizing plate 15 having on oneside or each side a single layer or multilayer of a compound orcompounds selected from AlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃. Thecircular polarizing plate 15 here has an AlN_(X)O_(Y) film 14 a on oneside and an AlN_(X)O_(Y) film 14 b on the other side.

[0063] Then the substrate 10 on which the layer 11 including an OLED orincluding an OLED and a TFT is formed is bonded to the circularpolarizing plate 15 having the AlN_(X)O_(Y) film 14 a on one side andthe AlN_(X)O_(Y) film 14 b on the other side using a bonding member 13to seal the device. The bonding member 13 is made of a material highlytransmissive of light, for example, an epoxy resin.

[0064] The light emitting device shown in FIG. 1 is thus obtained. Thelight emitting device shown in FIG. 1 emits light in the directionindicated by the arrow in FIG. 1 and uses the circular polarizing plate15 to prevent background images from being reflected on the screen. Thepresent invention is not limited to the device that emits light in thedirection of the arrow shown in FIG. 1 but is applicable to one thatemits light in the opposite direction to the arrow direction of FIG. 1.When the device emits light in the direction opposite to that of FIG. 1,a substrate transmissive of light is used as the substrate 10 and thecircular polarizing plate having AlN_(X)O_(Y) films is bonded to theside of the substrate 10 that does not have the layer 11 including anOLED or including an OLED and a TFT.

[0065]FIG. 12 shows the transmittance of an AlN_(X)O_(Y) film of 100 nmin thickness. As shown in FIG. 12, the light transmittance of theAlN_(X)O_(Y) film is very high (having a transmittance of 80 to 90% in avisible light range) and does not block light emitted from a lightemitting element.

[0066] In the present invention, an AlN_(X)O_(Y) film is formed bysputtering using, for example, an aluminum nitride (AlN) target in anatmosphere containing a mixture of argon gas, nitrogen gas, and oxygengas. It is sufficient if the AlN_(X)O_(Y) film formed contains severalatm % of nitrogen, preferably, 2.5 to 47.5 atm %. The nitrogenconcentration in the film can be adjusted by adjusting sputteringconditions (substrate temperature, the type and flow rate of materialgas, film formation pressure, and the like) suitably. The composition ofthe obtained AlN_(X)O_(Y) film is analyzed by ESCA (electronspectroscopy for analysis) and shown in FIG. 13. The AlN_(X)O_(Y) filmmay be formed using an aluminum (Al) target in an atmosphere containingnitrogen gas and oxygen gas. The method to form the AlN_(X)O_(Y) film isnot limited to sputtering, and evaporation or other known techniques maybe employed.

[0067] An experiment for confirming the effect of an AlN_(X)O_(Y) filmto block moisture and oxygen has been conducted. In the experiment, asample obtained by sealing an OLED with a film substrate on which anAlN_(X)O_(Y) film is formed to a thickness of 200 nm and a sampleobtained by sealing an OLED with a film substrate on which a SiN film isformed to a thickness of 200 nm are prepared and heated in a 85° C.steam atmosphere to observe their changes with time. According to theexperiment, the sample having the AlN_(X)O_(Y) film has longer OLEDlifetime and can emit light longer than the sample having the SiN film.It is read from the experiment result that an AlN_(X)O_(Y) film is moresuitable than a SiN film as a material film for preventing permeation ofmoisture, oxygen, and other external impurities that acceleratedegradation of an organic compound layer.

[0068] The effect of an AlN_(X)O_(Y) film to block an alkaline metal isconfirmed as follows:

[0069] A thermal oxide film with a thickness of 50 nm is formed on asilicon substrate, an AlN_(X)O_(Y) film with a thickness of 40 nm isformed thereon, and an aluminum electrode containing Li is formed on theAlN_(X)O_(Y) film. An aluminum electrode containing Si is formed on theside of the silicon substrate opposite to the side where the above filmsare formed and the substrate is heat-treated at 300° C. for an hour.Then a BT stress test (±1.7 MV/cm, 150° C., an hour) is performed on thesubstrate to measure the MOS characteristic (C-V characteristic). Theobtained C-V characteristic shifts to the plus side when a plus voltageis applied, in other words, when it is +BT. Therefore it is confirmedthat the cause of the shift is not Li but the AlN_(X)O_(Y) film exertingits alkaline metal blocking effect. For comparison, an insulating film(a silicon nitride film with a thickness of 100 nm) is formed on a MOSand an AlLi alloy film is formed on the insulating film to measure acharacteristic change of the MOS in a similar manner. The C-Vcharacteristic of this MOS greatly shifts to the minus side when a plusvoltage is applied, in other words, when it is +BT. The major cause ofthis is considered to be Li mixed in the active layer.

[0070] Embodiment Mode 2

[0071]FIGS. 2A and 2B are diagrams showing simplified examples of anorganic polarizing film according to the present invention.

[0072] The present invention also includes an organic polarizing filmhaving on one side a single layer or multilayer of a compound orcompounds selected from AlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃. An organicpolarizing film 21 with an AlN_(X)O_(Y) film 22 formed on one side isshown in FIG. 2A.

[0073] The present invention also includes an organic polarizing filmhaving on each side a single layer or multilayer of a compound orcompounds selected from AlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃. An organicpolarizing film 23 with an AlN_(X)O_(Y) film 24 a formed on one side andan AlN_(X)O_(Y) film 24 b formed on the other side is shown in FIG. 2B.

[0074] The term organic polarizing film here refers to a polarizing filmor a phase difference film, or a combination of the two and,specifically, it refers to a single layer or multilayer of polymerfilms. Polyvinyl alcohol-based films, ethylene vinyl alcohol-basedfilms, cellulose-based films, and polycarbonate-based films are given asexamples of an organic polarization film used in the present invention.

[0075] With a single layer or multilayer of a compound or compoundsselected from AlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃ formed on one side oreach side, an organic polarizing film can have a function of effectivelypreventing penetration of an alkaline metal, an alkaline earth metal,and other such impurities. In particular, when an AlN_(X)O_(Y) layer andan Al_(X)N_(Y) layer are used, an effect of diffusing generated heat isobtained as well as an effect of protecting the organic polarizing filmagainst deformation and alteration.

[0076] As shown in FIG. 12, the light transmittance of an AlN_(X)O_(Y)film is very high (having a transmittance of 80 to 90% in a visiblelight range) and therefore does not form an obstruction to thepolarizing function of the organic polarizing film.

[0077] The organic polarizing film thus obtained can be used as anantireflection film for electronic desktop calculators, electronicwatches, word processors, liquid crystal display devices for meters ofautomobiles and machines, sunglasses, dust-proof glasses, 3-D glasses,and display elements (CRTs, LCDs, and the like).

[0078] The organic polarizing film is very advantageous particularlywhen used as an antireflection means for preventing background imagesfrom being reflected on the screen of a light emitting device having anOLED since the film can also prevent oxygen and moisture from seepinginto an organic light emitting layer.

[0079] More detailed descriptions will be given on the present inventionstructured as above through the following embodiments.

[0080] Embodiment 1

[0081] An embodiment of the present invention is described withreference to FIGS. 3A to 3D and 4A to 4D. Here, a method ofsimultaneously manufacturing a CMOS circuit in which n-channel TFT andp-channel TFT are complementarily combined is described in detail.

[0082] First, the first material layer 101, the second material layer102, a base insulating film 103 are formed on a substrate 100 and asemiconductor film having a crystalline structure is obtained. Then, thesemiconductor film is etched to have a desired shape to formsemiconductor layers 104 and 105 separated from one another in an islandshape.

[0083] A glass substrate (#1737) is used as the substrate 100.

[0084] For the first material layer 101, it has a characteristic ofhaving a tensile stress within a range of 1 to 1×10¹⁰ (Dyne/cm²) afterthe filming process or directly before the peeling process. If materialsusing for the above-mentioned first material layer 101 having a tensilestress within the above-mentioned range, the material is notparticularly limited to specific materials. A layer or lamination layerfrom the following material can be used for the first material layer101; a metallic material (Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr,Zn, Ru, Rh, Pd, Os, Ir, and Pt, etc.), semiconductor materials (forinstance, Si and Ge, etc.), insulating materials or organic materials.Especially, a tungsten film, a tungsten nitride film or a titaniumnitride film is preferable. Note that, a film having a tensile stresswith more than 1 to 1×10¹⁰ (Dyne/cm²) is easy to peel in case ofapplying the heat treatment. Here, titanium nitride film having filmthickness of 100 nm laminated by a sputtering method is used. Note that,a buffer layer may be formed in the case that the first material layer101 is poorly adhered to the substrate 100.

[0085] For the second material layer 102, it has a characteristic ofhaving a compressive stress within a range of −1 to −1×10¹⁰ (Dyne/cm²).If materials using for the second material layer 102 have a compressivestress within the above-mentioned range, the material is notparticularly limited. Any one layer or a lamination layer of thefollowing material can be used for the second material layer 102; ametallic material (Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Zr, Zn,Ru, Rh, Pd, Os, Ir, and Pt, etc.), semiconductor materials (forinstance, Si and Ge, etc.), insulating materials or organic materials.Note that, a film having a compressive stress with more than −1×10¹⁰(Dyne/cm²) is easy to peel in case of applying the heat treatment.Especially, a single layer or a lamination layer composed of oxidesilicon material or oxide metal material is preferable. A silicon oxidefilm having film thickness of 200 nm laminated by a sputtering method isused. The bonding force between the first material layer 101 and thesecond material layer 102 is strong against the heat treatment, so thatthe film peeling (also referred to as peeling) or the like does notoccur. However, it can be easily peeled off on the inside of the secondmaterial layer or on the interface by the physical means.

[0086] For the base insulating film 103, a silicon oxynitride filmformed from SiH₄, NH₃, and N₂O as material gases (composition ratio:Si=32%, O=27%, N=24%, H=17%) is formed with a thickness of 50 nm(preferably 10 to 200 nm) and at a film deposition temperature of 400°C. by using plasma CVD. Then, after the surface is cleaned with ozonewater, an oxide film on the surface is removed by means of dilutehydrofluoric acid (dilution with {fraction (1/100)}). Next, a siliconoxynitride film formed from SiH₄ and N₂O as material gases (compositionratio: Si=32%, O=59%, N=7%, H=2%) is formed thereon with a thickness of100 nm (preferably 50 to 200 nm) and at a film deposition temperature of400° C. by using plasma CVD to thereby form a lamination. Further,without exposure to an atmosphere, a semiconductor film having anamorphous structure (in this case, amorphous silicon film) is formed tohave a thickness of 54 nm (preferably 25 to 80 nm) with SiH₄ as a filmdeposition gas and at a film deposition temperature of 300° C. by usingplasma CVD.

[0087] In this embodiment, the base film 103 is shown in a form of atwo-layer structure, but a single layer of the above-mentionedinsulating film or a structure in which two or more layers thereof arelaminated may be adopted. Further, there is no limitation on thematerial of the semiconductor film. However, the semiconductor film maybe preferably formed of silicon or silicon germanium (SiXGe1−X (X=0.0001to 0.02)) alloy by using a known means (sputtering, LPCVD, plasma CVD orthe like). Further, a plasma CVD apparatus may be a single wafer typeone or a batch type one. In addition, the base insulating film and thesemiconductor film may be continuously formed in the same film formationchamber without exposure to an atmosphere.

[0088] Subsequently, after the surface of the semiconductor film havingan amorphous structure is cleaned, an extremely thin oxide film with athickness of about 2 nm is formed from ozone water on the surface.

[0089] Then, a nickel acetate salt solution containing nickel of 10 ppmin weight is applied using a spinner. Instead of the application, amethod of spraying nickel elements to the entire surface by sputteringmay also be used.

[0090] Then, the heat treatment is conducted to perform crystallization,thereby forming a semiconductor film having a crystalline structure. Theheat treatment using an electric furnace or irradiation of strong lightmay be conducted for this heat treatment. In case of the heat treatmentusing an electric furnace, it may be conducted at 500 to 650° C. for 4to 24 hours. Here, after the heat treatment (500° C. for 1 hour) fordehydrogenation is conducted, the heat treatment (550° C. for 4 hours)for crystallization is conducted, thereby obtaining a silicon filmhaving a crystalline structure. Note that, although crystallization isperformed by using the heat treatment using a furnace, crystallizationmay be performed by means of a lamp annealing apparatus. Also note that,although a crystallization technique using nickel as a metal elementthat promotes crystallization of silicon is used here, other knowncrystallization techniques, for example, a solid-phase growth method anda laser crystallization method, may be used.

[0091] Next, after the oxide film on the surface of the silicon filmhaving a crystalline structure is removed by dilute hydrofluoric acid orthe like, irradiation of first laser light (XeCl: wavelength of 308 nm)for raising a crystallization rate and repairing defects remaining incrystal grains is performed in an atmosphere or in an oxygen atmosphere.Excimer laser light with a wavelength of 400 nm or less, or secondharmonic wave or third harmonic wave of a YAG laser or an YVO₄ laser isused for the laser light. Both the pulse oscillation and the continuousoscillitation are acceptable for the first laser light. In case ofapplying the pulse oscillitation, that of a repetition frequency is setto approximately 10 to 1000 Hz, the pulse laser light is condensed to100 to 500 mJ/cm² by an optical system, and irradiation is performedwith an overlap ratio of 90 to 95%, whereby the silicon film surface maybe scanned. Here, the irradiation of the first laser light is performedin an atmosphere with a repetition frequency of 30 Hz and energy densityof 393 mJ/cm². Note that an oxide film is formed on the surface by thefirst laser light irradiation since the irradiation is conducted in anatmosphere or in an oxygen atmosphere.

[0092] Next, after the oxide film formed by the first laser lightirradiation is removed by dilute hydrofluoric acid, the second laserlight irradiation is performed in a nitrogen atmosphere or in a vacuum,thereby the semiconductor film surface is leveled. Excimer laser lightwith a wavelength of 400 nm or less, or second harmonic wave or thirdharmonic wave of a YAG laser is used as the laser light (the secondlaser light). The energy density of the second laser light is madelarger than that of the first laser light, preferably made larger by 30to 60 mJ/cm². Here, the second laser light irradiation is performed witha repetition frequency of 30 Hz and energy density of 453 mJ/cm² tothereby set a P-V value (Peak to Valley, the difference between themaximum value and the minimum value in height) of unevenness in thesemiconductor film surface to 50 nm or less. Here, the P-V value ofunevenness may be obtained by AFM (atomic force microscope).

[0093] Further, although the second laser light irradiation is conductedover the surface in this embodiment, a step of selectively performingirradiation at least on a pixel portion may be adopted since thereduction of an off current particularly has an effect on a TFT of thepixel portion.

[0094] Next, the surface is processed with ozone water for 120 seconds,thereby forming a barrier layer comprised of an oxide film with athickness of 1 to 5 nm in total.

[0095] Then, an amorphous silicon film containing an argon element,which becomes a gettering site, is formed on the barrier layer to have athickness of 150 nm by sputtering. The film deposition conditions withsputtering in this embodiment are: a film deposition pressure of 0.3 Pa;a gas (Ar) flow rate of 50 sccm; a film deposition power of 3 kW; and asubstrate temperature of 150° C. Note that under the above conditions,the atomic concentration of the argon element contained in the amorphoussilicon film is 3×10²⁰/cm³ to 6×10²⁰/cm³, and the atomic concentrationof oxygen is 1×10¹⁹/cm³ to 3×10¹⁹/cm³. Thereafter, the heat treatment at650° C. for 3 minutes is conducted using the lamp annealing apparatus toperform gettering.

[0096] Subsequently, the amorphous silicon film containing the argonelement, which is the gettering site, is selectively removed with thebarrier layer as an etching stopper, and then, the barrier layer isselectively removed by dilute hydrofluoric acid. Note that there is atendency that nickel is likely to move to a region with a high oxygenconcentration in gettering, and thus, it is preferable that the barrierlayer comprised of the oxide film is removed after gettering. Although,the example of performing the gettering is shown here, there is noparticular limitation and other gettering method can be used.

[0097] Then, after a thin oxide film is formed from ozone water on thesurface of the obtained silicon film having a crystalline structure(also referred to as polysilicon film), a mask made of resist is formed,and an etching process is conducted thereto to obtain a desired shape,thereby forming the island-like semiconductor layers 104 and 105separated from one another. After the formation of the semiconductorlayers, the mask made of resist is removed.

[0098] Then, the oxide film is removed with the etchant containinghydrofluoric acid, and at the same time, the surface of the silicon filmis cleaned. Thereafter, an insulating film containing silicon as itsmain constituent, which becomes a gate insulating film 106, is formed.In this embodiment, a silicon oxynitride film (composition ratio:Si=32%, O=59%, N=7%, H=2%) is formed with a thickness of 115 nm byplasma CVD.

[0099] Next, as shown in FIG. 3B, on the gate insulating film 106, afirst conductive film 107 with a thickness of 20 to 100 nm and a secondconductive film 108 with a thickness of 100 to 400 nm are formed inlamination. In this embodiment, a 50 nm thick tantalum nitride film anda 370 nm thick tungsten film are sequentially laminated on the gateinsulating film 106.

[0100] As a conductive material for forming the first conductive filmand the second conductive film, an element selected from the groupconsisting of Ta, W, Ti, Mo, Al and Cu, or an alloy material or compoundmaterial containing the above element as its main constituent isemployed. Further, a semiconductor film typified by a polycrystallinesilicon film doped with an impurity element such as phosphorous, or anAgPdCu alloy may be used as the first conductive film and the secondconductive film. Further, the present invention is not limited to atwo-layer structure. For example, a three-layer structure may be adoptedin which a 50 nm thick tungsten film, an alloy film of aluminum andsilicon (Al—Si) with a thickness of 500 nm, and a 30 nm thick titaniumnitride film are sequentially laminated. Moreover, in case of athree-layer structure, tungsten nitride may be used in place of tungstenof the first conductive film, an alloy film of aluminum and titanium(Al—Ti) may be used in place of the alloy film of aluminum and silicon(Al—Si) of the second conductive film, and a titanium film may be usedin place of the titanium nitride film of the third conductive film. Inaddition, a single layer structure may also be adopted.

[0101] Next, as shown in FIG. 3C, masks 109 is formed by a lightexposure step, and a first etching process for forming gate electrodesand wirings is performed. An ICP (Inductively Coupled Plasma) etchingmethod may be preferably used for the etching process. The ICP etchingmethod is used, and the etching conditions (an electric energy appliedto a coil-shape electrode, an electric energy applied to an electrode ona substrate side, a temperature of the electrode on the substrate side,and the like) are appropriately adjusted, whereby a film can be etchedto have a desired taper shape. Note that chlorine-based gases typifiedby Cl₂, BCl₃, SiCl₄, CCl₄ or the like, fluorine-based gases typified byCF₄, SF₆, NF₃, or the like and O₂ can be appropriately used as etchinggases.

[0102] In the first etching process, the edges of the films can betapered owing to the shape of the resist mask and the effect of the biasvoltage applied to the substrate side. The angle of the tapered portionis set to 15 to 45°. In order to etch the films without leaving anyresidue on the gate insulating film, the etching time is prolonged byabout 10 to 20%. The selective ratio of the silicon oxynitride film tothe W film is 2 to 4 (typically, 3), and hence the exposed surface ofthe silicon oxynitride film is etched by about 20 to 50 nm through theover-etching treatment. Through the first etching treatment, the firstshape conductive layers 110 and 111 (first conductive layers 110 a and111 a and second conductive layers 110 b and 111 b) are formed from thefirst conductive film and the second conductive film. Reference numeral112 is a gate insulating film and a region of the gate insulating filmwhich is not covered with the first shape conductive layers is etchedand thinned by about 20 to 50 nm.

[0103] Then the first doping treatment is performed to dope the filmwith an n-type impurity (donor) (FIG. 3D). The doping is made by iondoping or ion implantation. In ion doping, the dose is set to 1×10¹³ to5×10¹⁴/cm². Used as the impurity element for imparting the n-typeconductivity is a Group 15 element, typically phosphorus (P) or arsenic(As). In this case, the first shape conductive layers 110 and 111 serveas masks against the element used for the doping and the accelerationvoltage is adjusted appropriately (20 to 60 keV, for example). Theimpurity element thus passes through the gate insulating film 112 toform impurity regions (n+ region) 113 and 114. For example, thephosphorus (P) concentration in the impurity regions (n+ region) is setto 1×10²⁰ to 1×10²¹/cm³.

[0104] Then, the second doping treatment is carried out as shown in FIG.4A. The film is doped with an n-type impurity (donor) in a dose smallerthan in the first doping treatment at a high acceleration voltage. Forexample, the acceleration voltage is set to 70 to 120 keV and the doseis set to 1×10¹³/cm². As a result, impurity regions are formed insidethe first impurity regions that have been formed in the semiconductorlayer in FIG. 3D. In the second doping treatment, the second conductivefilms 110 b and 111 b are used as masks against the impurity element andthe impurity element reaches regions below the first conductive films110 a and 111 a. Thus formed are impurity regions (n− region) 115 and116 that overlap the first conductive films 110 a and 111 a,respectively. Since the remaining first conductive layers 110 a and 111a have almost the uniform thickness, the concentration difference alongthe first conductive layers is small and the concentration in theimpurity regions is 1×10¹⁷ to 1×10¹⁹/cm³.

[0105] The second etching treatment is then conducted as shown in FIG.4B. In this etching treatment, ICP etching is employed, CF₄, Cl₂ and O₂are mixed as etching gas, and plasma is generated by giving RF (13.56MHz) power of 500 W to a coil-shape electrode at a pressure of 1 Pa. RF(13.56 MHz) power of 50 W is also given to the substrate side (samplestage) so that a self-bias voltage lower than that of the first etchingtreatment can be applied. The tungsten film is subjected to anisotropicetching under these conditions so that the tantalum nitride film or thetitanium film serving as the first conductive layers is remained. Inthis way, second shape conductive layers 117 and 118 (first conductivefilms 117 a and 118 a and second conductive films 117 b and 118 b) areformed. Reference numeral 119 is a gate insulating film and a region ofthe gate insulating film which is not covered with the second shapeconductive layers 117 and 118 is further etched and thinned by about 20to 50 nm.

[0106] Then, a mask 120 made of resist is formed as shown in FIG. 4C,and a p-type impurity (acceptor) is doped with the semiconductor layerthat forms the p-channel TFT. Typically, boron (B) is used. The impurityconcentration in impurity regions (p+ region) 121 and 122 is set withinthe range of 2×10²⁰ to 2×10²¹/cm³. In addition, the impurity regions aredoped with boron 1.5 to 3 times as much as phosphorus concentrationcontained in the impurity regions, thereby, the conductive type isinverted.

[0107] The impurity regions are formed in each semiconductor layerthrough the above steps. The second shape conductive layers 117 and 118serve as gate electrodes. Thereafter, as shown in FIG. 4D, a protectiveinsulating film 123 is formed of a silicon nitride film or a siliconoxynitride film by plasma CVD. The impurity elements that are doped thesemiconductor layers are then activated for controlling the conductivitytype.

[0108] A silicon nitride film 124 is formed and subjected tohydrogenation. Hydrogen is released from the silicon nitride film 124 asa result and hydrogen diffuses to the semiconductor layers. Thesemiconductor layers are thus hydrogenated.

[0109] An interlayer insulating film 125 is formed of an organicinsulating material such as polyimide, acrylic and the like. A siliconoxide film formed by plasma CVD using TEOS (Tetraethyl Ortho silicate)may of course be adopted instead, but it is preferable to choose theabove organic insulating material from the viewpoint of improvinglevelness.

[0110] Contact holes are formed next, so that source or drain wirings126 to 128 are formed from aluminum (Al), titanium (Ti), tantalum (Ta)or the like.

[0111] In accordance with the above processes, a CMOS circuit obtainedby combining an n-channel TFT and a p-channel TFT complementally isobtained.

[0112] A p-channel TFT has a channel formation region 130, and has theimpurity regions 121 and 122 that function as source regions or drainregions.

[0113] An n-channel TFT has a channel formation region 131; an impurityregion 116 a (Gate Overlapped Drain: GOLD region) overlapping the gateelectrode 118 that is formed of the second shape conductive layer; animpurity region 116 b (LDD region) formed outside the gate electrode;and an impurity region 119 functioning as a source region or a drainregion.

[0114] The CMOS circuit as such can be used to form a part of a drivercircuit of an active matrix type light emitting device or an activematrix type liquid crystal display device. Besides, the n-channel TFT orthe p-channel TFT as above can be applied to a transistor for forming apixel portion.

[0115] By combining the CMOS circuits of this embodiment, a basic logiccircuit, and further, a complicated logic circuit (such as a signaldivider circuit, a D/A converter, an operation amplifier, a γ correctioncircuit and the like) can be formed. It also can manufacture a memory ora microprocessor.

[0116] Embodiment 2

[0117] An example of fabrication of a light emitting device having anOLED by using TFTs obtained in Embodiment 1 will be described withreference to FIG. 5.

[0118]FIG. 5 shows an example of a light emitting device (in a statebefore sealing) having a pixel portion and a drive circuit for drivingthe pixel portion, the pixel portion and the drive circuit being formedon one insulating member. A CMOS circuit forming a basic unit in thedrive circuit and one pixel in the pixel portion are illustrated. TheCMOS circuit can be obtained in accordance with Embodiment 1.

[0119] Referring to FIG. 5, reference numeral 200 denotes a substrate,reference numeral 201 denotes a first material layer (such as W, WN, forexample), and reference numeral 202 denotes a second material layer(such as SiO₂, for example). On a base insulating layer 203 formed on aelement formation substrate, a driver circuit 204 constituted of an-channel TFT and a p-channel TFT, a switching TFT constituted of ap-channel TFT, and a current control TFT constituted of a n-channel TFTare formed. In this embodiment, each of the TFTs is formed as a top gateTFT.

[0120] A specific description of the n-channel TFT and the p-channel TFTis the same as those in Embodiment 1. Therefore, the description forthem is omitted in this embodiment. The switching TFT is a p-channel TFTof a structure having two channels forming regions between a sourceregion and a drain region (double-gate structure). In this embodiment,the structure of the switching TFT is not limited to the double-gatestructure, and the switching TFT may alternatively have a single-gatestructure in which only one channel forming region is formed or atriple-gate structure in which three channel forming regions are formed.

[0121] A contact hole is formed in a first interlayer insulating film207 above the drain region 206 of the current control TFT before asecond interlayer insulating film 208 is formed. This is for the purposeof simplifying the etching step when a contact hole is formed in thesecond interlayer insulating film 208. A contact hole is formed in thesecond interlayer insulating film 208 so as to reach the drain region206, and a pixel electrode 209 connected to the drain region 206 isformed in the contact hole. The pixel electrode 209 functions as thecathode of the OLED and is formed by using a conductive film containingan element belonging to the group I or II in the periodic table. In thisembodiment, a conductive film of a compound composed of lithium andaluminum is used.

[0122] Reference numeral 213 denotes an insulating film formed so as tocover an end portion of the pixel electrode 209, and this insulatingfilm will be referred to as a bank in this specification. The bank 213may be formed of an insulating film containing silicon or a resin film.If a resin film is used, carbon particles or metal particles may beadded to set the specific resistance of the resin film to 1×10⁶ to1×10¹² Ωm (preferably 1×10⁸ to 1×10¹⁰ Ωm), thereby reducing thepossibility of dielectric breakdown at the time of film forming.

[0123] The OLED 210 is formed by the pixel electrode (cathode) 209, anorganic compound layer 211, and an anode 212. As the anode 212, aconductive film of a large work function, typically an oxide conductivefilm is used. As this oxide conductive film, indium oxide, tin oxide,zinc oxide or some other compound of these elements may be used.

[0124] In this specification, organic compound layer is defined as ageneric name to a lamination layer formed by combining with a lightemitting layer, a hole injection layer, a hole transporting layer, ahole blocking layer, an electron transporting layer, an electroninjection layer, or an electron blocking layer. However, the organiccompound layer may comprise a single layer of organic compound film.

[0125] The material of the light emitting layer is an organic compoundmaterial but not limited to a particular one. It may be a high-molecularweight material or a low-molecular weight material. For example, a thinfilm formed of a light emitting material capable of emitting light bydoublet excitation or a thin film formed of a light emitting materialcapable of emitting light by triplet excitation may be used as the lightemitting layer.

[0126] It is effective to form a passivation film, not shown in thefigure here, so as to completely cover the OLED 210 after the formationof the anode 212. A film having thermal conductivity, for example, alayer shown by AlN_(x)O_(y), is suitably used as the passivation film.Also, an insulating film comprising a DLC film, a silicon nitride filmor a silicon oxynitride film, or a lamination layer formed of acombination of such films may be used as the passivation film.

[0127] After the sealing (or enclosure) process is conducted to protectthe OLED 210 by attaching a circular polarizing plate which has a singlelayer or a lamination layer selected from a layer shown by AlN_(x)O_(y),a layer shown by Al_(x)N_(y), or a layer shown by Al₂O₃ as shown inEmbodiment Mode 1 thereon, and then, a substrate 200 provided the firstmaterials 201 is peeled off. The second material layer and a filmsubstrate are bonded together with a bond layer. It is preferable thatplural barrier films and a layer that has a smaller stress (a stressrelaxation film) than that of the barrier films are provided on the filmsubstrate between the barrier films.

[0128] Note that the present invention can be implemented by combiningwith Embodiment Mode 2.

[0129] Embodiment 3

[0130] Here is shown an embodiment which is different from the processshown in the embodiment 2, and concretely, a peeling process and abonding process will be described in detail with reference to FIGS. 6Ato 6C and 7A and 7B.

[0131] In FIG. 6A, reference numeral 300 represents a substrate, 301represents a nitride layer, 302 represents an oxide layer, 303represents a base insulating layer, 304 a to 304 c represent elements,305 represents an OLED, and 306 represents an interlayer insulatingfilm.

[0132] In FIG. 6A, as the substrate 300, a glass substrate, a quartzsubstrate and a ceramic substrate can be used. Further, a siliconsubstrate, a metal substrate or a stainless steel substrate may be used.

[0133] Firstly, as shown in FIG. 6A, in accordance with the preferredEmbodiment Modes, on the substrate 300, a first material layer 301 and asecond material layer 302 are formed. It is important to differ filmstress of this first material layer 301 from film stress of the secondmaterial layer 302. Each film thickness may be set at pleasure to bewithin a range of 1 nm to 1000 nm and each film stress may be adjusted.

[0134] Then, on the second material layer 302, a layer to be peeled offis formed. The layer to be peeled off may be a layer which containsvarious elements as represented by TFT (a thin film diode, aphotoelectric conversion element having a PIN bonding with silicon and asilicon resistance element). Further, thermal processing can be carriedout within a range that the substrate 300 can resist. In addition, inthe invention, even when film stress of the second material layer 302 isdifferent from film stress of the first material layer 301, peeling doesnot occur by thermal processing in a process for forming the layer to bepeeled off. Here, as the layer to be peeled off, on the base insulatinglayer 303, elements 304 a to 304 b of the driving circuit 313 and anelement 304 c of the pixel portion 314 are formed, and an OLED 305 forelectrically connecting to the element 304 c of the pixel portion 314 isformed, and in order to cover the OLED, an interlayer insulating film(organic resin having translucency) 306 with film thickness of 10 to1000 nm is formed (FIG. 6A).

[0135] Further, in case that unevenness is made on a surface by thefirst material layer 301 and the second material layer 302, the surfacemay be planarized before and after the base insulating layer is formed.Coverage is made to be better in the layer to be peeled off in case thatplanarization is carried out, and in case that the layer to be peeledoff containing an element is formed, element characteristic is apt to bestabilized and therefore, it is preferable. In addition, as thisplanarization processing, an etch-back method for planarizing bycarrying out an etching after a coating film (such as a resist film) isformed and a mechanical chemical polishing method (a CMP method) may beused.

[0136] Then, on the interlayer insulating film 306, formed is a nitrideoxide film 307 which is represented by an AlNxOy film with thickness of10 to 1000 nm and contains aluminum (FIG. 6B). This AlNxOy film 307functions as a protective film. Here, by use of an aluminum nitride(AlN) target, film forming is carried out under an atmosphere in whichargon gas (20 sccm), nitrogen gas (15 sccm) and oxygen gas (5 sccm) aremixed. Further, by use of an aluminum (Al) target, film forming may becarried out under an atmosphere which contains the nitrogen gas and theoxygen gas. Furthermore, the AlNxOy film 307 has also an advantage forblocking intrusion of a material which expedites deterioration of theOLED, something like impurities such as moisture and oxygen from outsideof the device.

[0137] Then, an FPC 310 and an IC chip (not shown in the figure) areattached by a COG (chip on glass) system, a TAB (tape automated bonding)system and a wire bonding method. Further, each wiring of each TFTelements and an input/output terminal 311 are coupled by a wiring(connecting wiring), and the FPC 310 is adhered to the input/outputterminal 311 by an anisotropic conductive member. The anisotropicconductive member comprises a resin and a conductive particle withdiameter of several dozen to several hundred μm on which surface, Au orthe like is plated, and the input/output terminal and the wiring formedon the FPC are electrically connected by the conductive particle. An ICchip which has a memory, a CPU, a controller, a D/A converter and thelike is adhered to the substrate in the same manner by the anisotropicconductive member, and by the conductive particle which is mixed in theresin, the input/output terminal disposed in the IC chip and a leaderline or a connecting wiring and the input/output terminal areelectrically connected.

[0138] Then, a supporting body (a circular polarizing plate 309 a onwhich AlNxOy film 309 b is provided) 309 for fixing the layer to bepeeled off to peel the substrate 300 by a physical means is attached byan adhesive layer 308 such as epoxy resin (FIG. 6C). Further, AlNxOyfilm which functions as a barrier film is provided on the circularpolarizing plate 309 a, therefore, the AlNxOy film can sufficientlyprevent the intrusion of the impurities such as moisture and oxygen frominto the organic light emitting layer.

[0139] Since the supporting body 309 is attached to cover the FPC 310and the IC chip, connection of the input/output terminal 311 and the FPCis more strengthened by adhesion of the supporting body 309. Further,here was shown the example in which the supporting body is adhered afterthe FPC and the IC chip were adhered, but the FPC and the IC chip may bemounted after the supporting body is adhered.

[0140] Then, the substrate 300 on which the first material layer 301 isformed is peeled off by the physical means. Since film stress of thesecond material layer 302 is different from film stress of the firstmaterial layer 301, it is possible to peel off by relatively smallforce. A bonding force of the first material layer 301 and the secondmaterial layer 302 has strength which can resist against thermal energyand, since respective film stresses are different and stress distortionexists between the first material layer 301 and the second materiallayer 302, it is weak to mechanical energy, and it is optimum to peeloff. Thus, the layer to be peeled off which is formed on the secondmaterial layer 302 can be peeled off from the substrate 300. FIG. 7Ashows a state after the peeling. In addition, this method of peeling isapplied to the peeling of the layer to be peeled off having a smallarea, and besides, it is possible to peel off in all surfaces of thelayer to be peeled off having a large area with good yield ratio.

[0141] Then, the second material layer 302 is attached to a transferringbody 312 a by the adhesive layer 308 such as epoxy resin. In thisembodiment, shown is an example in which the adhesive layer is adheredto the protective film 307.

[0142] Further, here, weight saving is carried out by use of a plasticfilm substrate as the transferring body 312 a. Furthermore, by disposinga lamination layer of a layer which functions as a barrier film and isrepresented by AlNxOy (called as AlNxOy film) 312 b and a stressrelaxation film (organic resin) 312 c and an AlNxOy film 312 d on thetransferring body 312 a, the barrier film effectively prevents intrusionof impurities such as moisture and oxygen in an organic light emittinglayer. At the same time, a light emitting device having more flexibilitycan be obtained by providing a stress relaxing film between a pluralityof barrier films, and an occurrence of crack can be prevented.

[0143] Thus, a light emitting device comprising an OLED formed on aplastic substrate having flexibility is completed.

[0144] In this specification, the transferring body is bonded to thelayer to be peeled off after the peeling. The transferring body is notlimited to a material having any composition, for example, plastic,glass, metal, ceramic or the like can be used as the transferring body.The shape of the transferring body and the supporting body is notlimited, the shape may be a plane or a film and have a curved surface.If the lightening is prioritized, a film plastic substrate is preferableas follows, for example, polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC),nylon, polyether ether ketone (PEEK), polysulfone (PSF), polyether imide(PEI), polyarylate (PAR), polybutylene terephthalate (PBT) or the like.

[0145] Note that the present embodiment can be implemented by combiningwith Embodiment Mode 2.

[0146] Embodiment 4

[0147] Although, an example of cohering with a circular polarizing plateby adhering an adhesive layer with a protective film is shown inEmbodiment 3, an example of an air gap provided between a circularpolarizing plate and a protective film is described with reference toFIGS. 8A to 8B in this embodiment.

[0148]FIG. 8A is a top view which shows an EL module, and FIG. 8B is asectional view cut along a line of A-A′ of FIG. 8A. In FIG. 8B, a layer810 b which functions as a barrier film at a surface and is representedby AlNxOy (called also as an AlNxOy film), a stress relaxation film(organic resin) 810 c, and a film substrate 810 a (such as a plasticsubstrate, for example) having flexibility on which surface disposed isa lamination layer of an AlNxOy film 810 d are adhered to an insulatingfilm 811 by an adhesive layer 833. In addition, a material which stressis smaller than that of the barrier film may be used as the adhesivelayer 833 and it may be made to function as a stress relaxation film. Asjust described, by layering a plurality of barrier films 810 b and 810d, even in case that the barrier film suffers some cracks, other barrierfilm effectively prevents impurities such as moisture and oxygen fromgetting into the organic light emitting layer. In addition, by disposingthe stress relaxation film between a plurality of barrier films,obtained is a light emitting device which is more flexible and cracksmay be prevented when it is bent.

[0149] In addition, here, insulating films 811 and 820 are disposed on asubstrate having heat resistance, a pixel portion 812, a source sidedriving circuit 814 and a gate side driving circuit 813 are formedthereon, and thereafter, a covering member which is a circularpolarizing plate 830 a in this embodiment is adhered to fix them and thesubstrate having heat resistance is peeled off, and thereafter, the filmsubstrate is attached, but this is not particularly limited, and itshould be appreciated that the film substrate may be a film substratewhich can resist temperature for forming the pixel portion 812, thesource side driving circuit 814 and the gate side driving circuit 813,and the pixel portion 812, the source side driving circuit 814 and thegate side driving circuit 813 are formed on the film substrate and inthat case, it is not necessary to dispose an adhesive layer.

[0150] A technology for peeling the substrate having heat resistant (aglass substrate and a quartz substrate) is not limited particularly, andhere, used is a method for peeling by use of internal stress of a film,to be more precise, a method in which disposed on the substrate havingheat resistance is a lamination film of a first material layer and asecond material layer in which abnormality on a process such as peelingdue to thermal processing does not occur and an element (TFT and a lightemitting element) is formed on the lamination layer and thereafter, itis finely separated easily in a layer or a boundary surface of thesecond material layer by physical means, typically by applying amechanical force, for example, peeling off by use of a human hand. Sincea bonding force of the first material layer and the second materiallayer has a strength which can resist against thermal energy and rightbefore peeling, has a stress distortion between the first material layerhaving tensile stress and the second material layer having compressionstress, it is weak to mechanical energy and thus the first and secondmaterial layers are peeled off. Here, since the peeling was carried outby using a tungsten film as the first material layer and by using asilicon oxide film by spattering method as the second material layer,the insulating film 811 corresponds to the second material layer.

[0151] Further, as another technology for peeling off the substratehaving heat resistance, a peeling method for peeling off a layer to bepeeled off through a separation layer from the substrate (JapanesePatent Laid-Open No. 10-125929 gazette, Japanese Patent Laid-Open No.10-125931 gazette) may be used. A technology described in the gazettesis one in which a separation layer which comprises amorphous silicon (orpolysilicon) is disposed, and hydrogen contained in the amorphoussilicon is discharged by irradiating laser light through the substrateso that an air gap is formed and thereby, the substrate is separated.

[0152] In FIG. 8B, on the insulating film 820, the pixel portion 812 andthe gate side driving circuit 813 are formed, and the pixel part 812 isformed by a plurality of pixels containing a TFT 821 for current controland a pixel electrode (cathode) 822 which is electrically connected toits drain. As the TFT 821 for current control, it is possible to use ap-channel TFT but preferable to use an n-channel TFT. Further, the gateside driving circuit 813 is formed by use of a CMOS circuit which isconfigured by combining an n-channel TFT 823 and a p-channel TFT 824. Asan active layer of each TFT, a semiconductor film (polysilicon film)having a crystalline structure and a semiconductor film (for example,amorphous silicon film) having an amorphous structure are used.

[0153] Further, the pixel electrode 822 functions as a cathode of alight emitting element (OLED). Furthermore, at both sides of the pixelelectrode 822, a bank 825 is formed, and on the pixel electrode 822, anorganic compound layer 826 and an anode 827 of the light emittingelement are formed.

[0154] As the organic compound layer 826, it should be appreciated thatthe organic compound layer (a layer for carrying out light emission andmovement of carriers therefor) may be formed by freely combining a lightemitting layer, an electric charge transport layer or an electric chargeinjection layer. For example, low molecular series organic compoundmaterial and high molecular series organic compound material may beused. Further, as the organic compound layer 826, a thin film whichcomprises a light emitting material (singlet compound) which emits lightby singlet excitation, or a thin film which comprises a light emittingmaterial (triplet compound) which emits light (phosphorous light) bytriplet excitation may be used. Furthermore, it is possible to use aninorganic material such as silicon carbide as the electric chargetransport layer and the electric charge injection layer. As theseorganic and inorganic materials, well-know materials can be used.

[0155] The anode 827 functions as a common wiring to all pixels, and iselectrically connected to an FPC 819 through a connection wiring 818.Further, elements which are contained in the pixel portion 812 and thegate side driving circuit 813 are all covered by the anode 827, anorganic resin 828 and a protective film 829.

[0156] Further, in FIG. 8A, reference numeral 828 represents the organicresin and 829 represents the protective film, and the pixel portion 812and driving circuits 813 and 814 are covered by the organic resin 828,and the organic resin is covered by the protective film (AlNxOy film)829. In addition, as the organic resin 828, it is preferable to use atransparent or half transparent material to visible light to the extentpossible. Further, it is preferable that the organic resin 828 is amaterial which does not transmit impurities such as moisture and oxygento the extent possible.

[0157] Moreover, the pixel portion 812 and the driving circuits 813 and814 are sealed by a circular polarizing plate 830 a by use of adhesive.The circular polarizing plate 830 a is adhered as a supporting bodybefore peeling. In addition, in case that the peeling is carried outafter the circular polarizing plate 830 a as the supporting body isadhered, there exist only insulating films 820 and 811 at a portion of awiring lead-out terminal (connecting portion) and mechanical strength isweakened and therefore, before peeling, the FPC 819 is affixed andfurther, fixed by an organic resin 832.

[0158] Here, it is preferable that in order to resist againsttransformation due to heat or external force, as the circular polarizingplate 830 a, one which is the same material as the film substrate 810 a,for example, a plastic substrate may be used. In addition, in order toblock intrusion of impurities such as moisture and oxygen, an AlNxOyfilm 830 b is formed in advance on the circular polarizing plate 830 a.Here, in order to transmit emitting light through the circularpolarizing plate, a barrier layer (AlNxOy film 830 b) as a single layerwas used, but in the same manner as in the film substrate 810 a, aplurality of barrier layers and a layer (stress relaxation film) whichis disposed between the barrier layers and has smaller stress than thatof the barrier layer may be used. In that case, as a stress relaxationfilm, one that has high translucency is used.

[0159] In addition, reference numeral 818 represents a wiring fortransmitting signals to be inputted into the source side driving circuit814 and the gate side driving circuit 813, and it receives a videosignal and a clock signal from the FPC (flexible print circuit) 819which becomes an external input terminal. In addition, here, only FPC isshown in the figure, but a printed wiring board (PWB) may be attached tothis FPC. An EL module in the present specification is assumed tocontain not only a main substrate on which a light emitting element isdisposed but also a state in which FPC or PWB is attached thereto.

[0160] By sealing the light emitting element by the barrier films 810 band 810 d represented by AlNxOy and the protective film 829 representedby AlNxOy by use of the above-described structure, the light emittingelement can be completely blocked from an ambient air and it is possibleto block intrusion of a material for inducing deterioration of whichmain cause is oxidization of the organic compound layer by moisture andoxygen from outside of the device. In addition, heat developed can beexhaled by AlNxOy film having a thermal conduction characteristic.Accordingly, it is possible to obtain a light emitting device which hashigh reliability.

[0161] In addition, by disposing a stress relaxation film between pluralbarrier films, obtained is a light emitting device which is not brokeneven when an external force is applied and flexible.

[0162] Incidentally, on the film substrate 810 a, the pixel portion 812,the driving circuit and the light emitting element are disposed. It ispossible to form complex integrated circuits (such as a memory, a CPU, acontroller and a D/A converter) on the same substrate as that on whichthese pixel portion and the driving circuit are formed, but it isdifficult to manufacture it by use of small number of masks.Accordingly, it is preferable to carry out mounting one IC chip whichhas the memory, the CPU, the controller and the D/A converter by a COG(chip on glass) system, a TAB (tape automated bonding) system and a wirebonding method. It should be appreciated that the IC chip may be mountedafter the film substrate 810 a and the circular polarizing plate 830 aare adhered, and the IC chip may be sealed by the circular polarizingplate 830 a after the IC chip is mounted on the film substrate 810 a.

[0163] Incidentally, here, only FPC is shown in the figure but a printedwiring board (PWB) may be attached to this FPC.

[0164] Further, it should be appreciated to form a structure in whichthe pixel electrode is made to be an anode, and the organic compoundlayer and the cathode are layered, and light is emitted in an oppositedirection to FIG. 8. In that case, it is preferable to use the p-channeltype TFT as the TFT for current control.

[0165] Note that this embodiment can be implemented by combining withEmbodiment Mode 2.

[0166] Embodiment 5

[0167] In this embodiment, a pixel electrode is used as an anode and anorganic compound layer and a cathode are laminated to emit light in adirection opposite to the direction indicated in the Embodiment 4 (FIG.8). FIG. 9 shows an example of such a structure. The top view is notillustrated because it is same as FIG. 8A.

[0168] The cross-sectional structure shown in FIG. 9 is described. Acircular polarizing plate 1000 a provided with the lamination layercomposed of a AlNxOy film 1000 b, a stress relaxation film 1000 c and aAlNxOy film 1000 d is bonded to the insulating film 1001 with anadhesive layer 1023. An insulating film 1010 is formed on the insulatingfilm 1001. The pixel portion 1002 and the gate driving circuit 1003 areformed above the insulating film 1010. The pixel portion 1002 iscomposed of the current control TFT 1011 and plural pixels including thepixel electrode 1012 that is connected electrically to the drain of thecurrent control TFT 1011. The current control TFT 1011 is possible touse an n-channel TFT, however, it is prefer to use a p-channel TFT. Inaddition, the gate driving circuit 1003 is formed by using a CMOScircuit that is combined with the n-channel TFT 1013 and the p-channelTFT 1014.

[0169] These TFTs (included 1011, 1013, 1014) may be fabricated in thesame manner as an n-channel TFT 201 and a p-channel TFT 202 inEmbodiment 1.

[0170] The pixel electrode 1012 functions as an anode of the lightemitting element (OLED). Banks 1015 are formed at opposite ends of thepixel electrode 1012, and an organic compound layer 1016 and a cathode1017 of the light emitting element are formed over the pixel electrode1012.

[0171] The cathode 1017 also functions as a common wiring elementconnected to all the pixels and is electrically connected to a FPC 1009via connection wiring 1008. All the elements included in the pixelportion 1002 and the gate driving circuit 1003 are covered with thecathode 1017, an organic resin 1018 and a protective film 1019. It ispossible to apply the AlNxOy film the same as the AlNxOy film 1000 b asthe protective film 1019 and it is bonded to a cover member 1020 by anadhesive layer. A recess portion is formed in the cover member and adesiccant 1021 is set therein.

[0172] In the case where the cover member 1020 is formed so as to have acavity as shown in FIG. 9, a portion corresponding to the wiringlead-out terminal is only the insulating film 1010 at the time ofpeeling-off after bonding of the cover member 1020 provided as thesupporting member, and then the mechanical strength of this portion islow. Therefore, it is desirable that the FPC 1009 be attached beforepeeling-off and fixed by an organic resin 1022.

[0173] In the FIG. 9, the pixel electrode is used as the anode while theorganic compound layer and the cathode are laminated, so that light isemitted in the direction of the arrow in FIG. 9.

[0174] While the top gate TFTs have been described as an example, thepresent invention can be applied irrespective of the TFT structure. Forexample, the present invention can be applied to bottom gate (invertedstaggered structure) TFTs and staggered structure TFTs.

[0175] Note that the present invention can be implemented by combiningwith Embodiment Mode 2.

[0176] Embodiment 6

[0177] The EL module formed by implementing the present invention can beused in various display portions of electronic apparatuses. That is, thepresent invention can be implemented in all of electronic apparatusintegrated with the EL modules at display portions thereof.

[0178] As such electronic apparatus, there are pointed out a videocamera, a digital camera, a head mount display (goggle type display), acar navigation system, a projector, a car stereo, a personal computer, aportable information terminal (such as mobile computer, portabletelephone or electronic book) and the like. Examples of these are shownin FIGS. 10A to 10F, and 11A to 11C.

[0179]FIG. 10A shows a personal computer including a main body 2001, animage input portion 2002, a display portion 2003, a keyboard 2004 andthe like.

[0180]FIG. 10B shows a video camera including a main body 2101, adisplay portion 2102, a voice input portion 2103, operation switches2104, a battery 2105, an image receiving portion 2106 and the like.

[0181]FIG. 10C shows a mobile computer including a main body 2201, acamera portion 2202, an image receiving portion 2203, an operationswitch 2204, a display portion 2205 and the like.

[0182]FIG. 10D shows a goggle type display including a main body 2301, adisplay portion 2302, an arm portion 2303 and the like.

[0183]FIG. 10E shows a player using a record medium recorded withprograms (hereinafter, referred to as record medium) including a mainbody 2401, a display portion 2402, a speaker portion 2403, a recordmedium 2404, an operation switch 2405 and the like. The player uses DVD(Digital Versatile Disc), CD and the like as the record medium and canenjoy music, enjoy movie and carry out games or Internet.

[0184]FIG. 10F shows a digital camera including a main body 2501, adisplay portion 2502, an eye contact portion 2503, operation switches2504, an image receiving portion (not illustrated) and the like.

[0185]FIG. 11A shows a portable telephone including a main body 2901, asound output portion 2902, a sound input portion 2903, a display portion2904, an operation switch 2905, an antenna 2906, an image input portion(CCD, image sensor or the like) 2907 and the like.

[0186]FIG. 11B shows a portable book (electronic book) including a mainbody 3001, display portion 3002, 3003, a record medium 3004, anoperation switch 3005, an antenna 3006 and the like.

[0187]FIG. 11C shows a display including a main body 3101, a supportbase 3102, a display portion 3103 and the like.

[0188] Note that, the display shown in FIG. 11C is small and medium typeor large type, for example, a screen of the display sized 5 to 20inches. Moreover, it is preferable to mass-produce by executing amultiple pattern using a substrate sized 1×1 m to form such sizeddisplay section.

[0189] As has been described, the range of applying the presentinvention is extremely wide and is applicable to electronic apparatusesof various fields. The electronic apparatus of the present invention canbe implemented by freely combined with the structures in Embodiments 1to 5.

[0190] The present invention can provide a light emitting device whichis capable of suppressing deterioration due to diffusion of impuritiessuch as moisture, oxygen, an alkaline metal and an alkaline earth metal.In addition, in the case where a barrier film (a AlN_(X)O_(Y) film or alayer denoted by Al_(X)N_(Y)) having high thermal conductivity is formedon a circular polarizing plate, the present invention provides suchadvantages that heat developed in the element is spread so as tosuppress the deterioration of the element, and transformation anddegeneration of a circular polarizing film are protected while functionsof a circular polarizing means are maintained.

What is claimed is:
 1. A light emitting device comprising a lightemitting element, the light emitting element comprising: a cathode; anorganic compound layer in contact with the cathode; and an anode incontact with the organic compound layer, wherein the light emittingdevice is provided with a circular polarizing plate having a singlelayer or multilayer of AlN_(X)O_(Y).
 2. A light emitting deviceaccording to claim 1, wherein the circular polarizing plate has a singlelayer or multilayer of AlN_(X)O_(Y) on one side thereof or on each sidethereof.
 3. A light emitting device according to claim 1, wherein thecircular polarizing plate has a single layer or multilayer ofAlN_(X)O_(Y) on one side thereof and has a bonding member on the otherside thereof.
 4. A light emitting device according to claim 1, whereinthe circular polarizing plate is interposed between the light emittingelement and a viewer (observer), and is positioned at some point alongthe light path that starts with emission of light from the lightemitting element and ends with arrival of the light at the viewer.
 5. Alight emitting device according to claim 4, wherein the AlN_(X)O_(Y)layer(s) contain(s) 2.5 to 47.5 atm % of nitrogen.
 6. A light emittingdevice according to claim 1, wherein the AlN_(X)O_(Y) layer(s) is (are)50 to 500 nm in thickness.
 7. A light emitting device comprising a lightemitting element sandwiched between a first substrate and a secondsubstrate, the light emitting element comprising: a cathode; an organiccompound layer in contact with the cathode; and an anode in contact withthe organic compound layer, wherein the first substrate or the secondsubstrate is a plastic substrate, and wherein the plastic substrate isprovided with a circular polarizing plate having a single layer ormultilayer of a compound or compounds selected from AlN_(X)O_(Y),Al_(X)N_(Y), and Al₂O₃.
 8. A light emitting device according to claim 7,wherein the circular polarizing plate is fixed to the first substrate orthe second substrate by a bonding member.
 9. A light emitting deviceaccording to claim 1, wherein the light emitting device is applied to anelectronic apparatus selected from the group consisting of a videocamera, a digital camera, a goggle-type display, a car navigationsystem, a personal computer, and a portable information terminal.
 10. Alight emitting device according to claim 7, wherein the light emittingdevice is applied to an electronic apparatus selected from the groupconsisting of a video camera, a digital camera, a goggle-type display, acar navigation system, a personal computer, and a portable informationterminal.
 11. An organic polarizing film having on its film surface asingle layer or multilayer of a compound or compounds selected fromAlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃.
 12. An organic polarizing filmaccording to claim 11, wherein the single layer or multilayer of acompound or compounds selected from AlN_(X)O_(Y), Al_(X)N_(Y), and Al₂O₃is (are) 50 to 500 nm thick in total.
 13. A light emitting devicecomprising: a thin film transistor over a substrate; a first insulatingfilm over the thin film transistor; a first electrode over the firstinsulating film and connected to the thin film transistor through a holeformed in the first insulating film; a light emitting layer comprisingan organic compound over the first electrode; a second electrode overthe light emitting layer; a second insulating film comprisingAlN_(X)O_(Y) over the second electrode; a circular polarizing platehaving at least a layer comprising AlN_(X)O_(Y).
 14. A light emittingdevice comprising: at least one first insulating film comprisingAlN_(X)O_(Y) over a substrate; a thin film transistor over thesubstrate; a second insulating film over the thin film transistor; afirst electrode over the second insulating film and connected to thethin film transistor through a hole formed in the second insulatingfilm; a light emitting layer comprising an organic compound over thefirst electrode; a second electrode over the light emitting layer; athird insulating film comprising AlN_(X)O_(Y) over the second electrode;a circular polarizing plate having at least a layer comprisingAlN_(X)O_(Y).